Sealing gas inflow control monitoring system

Abstract

The utility model belongs to the field of mechanical sealing equipment, and particularly provides a sealing gas inlet amount control monitoring system which comprises a first pipeline, a second pipeline, a gas inlet end, a gas outlet end, a gas inlet control valve, a gas outlet control valve and a gas outlet control valve, wherein the gas inlet end is connected to a carbon ring sealing high-temperature and high-pressure gas source; the air outlet end is connected to a carbon ring sealing air injection port at the shaft end of the compressor for air intake and pressure tapping; the head end of the second pipeline is connected to a shaft section sealing position at the root of an outlet impeller of the compressor for pressure tapping; and the pressure difference transmitter A is connected to the first pipeline and the second pipeline and used for measuring the pressure difference between the pressure of gas entering the carbon ring seal and the root of the compressor impeller, and a signal of the pressure difference transmitter feeds back a pressure difference signal to the positioner through a secondary instrument of a control room. According to the scheme, a clean gas source is provided for a sealing system of the compressor, the gas inlet amount of sealing gas can be adjusted through the adjusting valve and the pressure difference transmitter, the sealing operation condition can be effectively monitored, the system can give an alarm in time when sealing fails, and maintenance workers can deal with field accidents at the fastest speed.

Description

Technical Field

[0001] The utility model belongs to the field of mechanical seal equipment, and particularly provides a sealing gas intake control and monitoring system for a carbon ring of a compressor (high temperature and high pressure). Background Art

[0002] The production safety problems, environmental pollution problems and energy conservation problems caused by the seal leakage of compressors and steam turbines have become important issues that are generally concerned by the country, society and the industry. In order to ensure the better production safety operation of the carbon ring seals of centrifugal compressors and steam turbines in energy storage power generation projects, reduce environmental pollution, save energy, ensure the better operation of the shaft end carbon ring seals and extend the seal life. It is urgent to develop a system that can detect the sealing gas leakage of the compressor carbon ring and control the sealing gas intake. Summary of the Utility Model

[0003] To solve the above technical problems, the utility model provides a sealing gas intake control and monitoring system for monitoring and controlling the amount of sealing gas entering the carbon ring of the compressor seal. The control and monitoring system includes,

[0004] A first pipeline, the intake end of which is connected to a high-pressure gas source cooled by the high-temperature and high-pressure process gas at the outlet of the compressor, and is provided with an intake regulating valve; the outlet end is connected to the intake and pressure taking of the carbon ring seal gas injection port at the shaft end of the compressor;

[0005] A second pipeline, the head end of which is connected to take pressure before the shaft section seal at the root of the impeller at the outlet of the compressor;

[0006] A differential pressure transmitter A, which is respectively connected to the first pipeline and the second pipeline, and is used to measure the pressure difference between the gas pressure entering the carbon ring seal and the pressure at the root of the compressor impeller;

[0007] The differential pressure transmitter is connected to the regulating valve, and the regulating valve adjusts the intake according to the differential pressure signal transmitted by the differential pressure transmitter.

[0008] Further, on the intake end of the first pipeline, a gas filtering unit is provided before entering the regulating valve.

[0009] Further, pressure is taken on the pipelines at both ends of the gas filtering unit respectively, and a differential pressure transmitter B is provided to detect whether the filtering unit is blocked by detecting the change of the differential pressure.

[0010] Further, on the intake pipeline of the first pipeline, a cooler is also provided before entering the regulating valve to cool the injected high-temperature and high-pressure gas.

[0011] Further, a temperature transmitter, a pressure transmitter A and a cooling tank are sequentially arranged on the second pipeline.

[0012] Further, a drain valve is provided at the bottom of the cooling tank for automatically discharging the condensed water in the cooling tank.

[0013] Further, an alarm unit is further included, and the differential pressure transmitter A is signal-connected to the alarm unit. Normal value and minimum value alarms are set on the differential pressure transmitter A.

[0014] The advantages of the present utility model are as follows: A gas treatment, regulation, monitoring and control system panel station with a novel special working condition (extra-high temperature) multi-stage floating carbon ring combined seal is provided. This solution provides a clean gas source for the sealing system of the compressor. Through the feedback of the pressure difference value monitored by the differential pressure transmitter A, not only can the intake air volume of the sealing gas be adjusted, but also the operation condition of the seal can be effectively monitored. When the seal fails, the system can alarm in time, which is beneficial for maintenance workers to handle on-site accidents at the fastest speed. Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of the present utility model;

[0016] Wherein, 1. First pipeline; 2. Compressor; 3. Thin film regulating valve (with positioner and valve position feedback); 4. Second pipeline; 5. Differential pressure transmitter A; 6. Gas filtering unit; 7. Differential pressure transmitter B; 8. Cooler; 9. Temperature transmitter; 10. Pressure transmitter A; 11. Cooling tank; 12. Pressure transmitter B. Specific Embodiments

[0017] The principles and features of the present utility model are described below with reference to the accompanying drawings. The examples given are only used to explain the present utility model and are not intended to limit the scope of the present utility model.

[0018] For the multi-stage carbon ring seal of the high-pressure and high-temperature compressor, the carbon ring seal is an assembled 4-section carbon ring seal. The sealing graphite ring is integrally inlaid. The first-stage seal is a single-ring seal (barrier seal), the second-stage and third-stage seals are 2-ring seals (pressure-dividing and gas-introducing seals), and the fourth-stage 3-ring and comb-tooth seal combination (isolation seal). In order to ensure the efficiency of the compressor, the compressor requires that the sealing gas flow entering the compressor through the barrier seal is small.

[0019] Refer to Figure 1 , the present utility model provides a sealing gas intake volume control and monitoring system for monitoring and controlling the sealing gas volume entering the sealing carbon ring of the compressor. The control and monitoring system includes,

[0020] The first pipeline, the intake end is connected to the high-temperature and high-pressure gas source of the carbon ring seal, connected to the compressor outlet, and an intake regulating valve is provided thereon; the outlet end is connected to the intake and pressure-taking port of the carbon ring seal gas injection port at the compressor shaft end;

[0021] The second pipeline, with its head end connected to take pressure before the shaft segment seal at the root of the compressor outlet impeller;

[0022] Differential pressure transmitter A, which is respectively connected to the first pipeline and the second pipeline, and is used to measure the pressure difference between the gas pressure entering the carbon ring seal and the pressure at the root of the compressor impeller;

[0023] The differential pressure transmitter is connected to a regulating valve, and the regulating valve adjusts the intake air volume according to the differential pressure signal transmitted by the differential pressure transmitter.

[0024] As an improvement to the solution, on the intake end of the first pipeline, a gas filtering unit is provided before entering the regulating valve.

[0025] As an improvement to the solution, on the pipelines at both ends of the gas filtering unit, a pressure is taken respectively on each pipeline, and a differential pressure transmitter B is provided to detect whether the filtering unit is blocked by detecting the change in differential pressure.

[0026] As an improvement to the solution, on the intake end pipeline of the first pipeline, a cooler is also provided before entering the regulating valve to cool the injected high-temperature and high-pressure gas.

[0027] As an improvement to the solution, a temperature transmitter, a pressure transmitter A and a cooling tank are successively arranged on the second pipeline.

[0028] As an improvement to the solution, a drain valve is provided at the bottom of the cooling tank for automatically discharging the condensed water in the cooling tank.

[0029] As an improvement to the solution, an alarm unit is further included, and the differential pressure transmitter A is signal-connected to the alarm unit.

[0030] As an improvement to the solution, a pressure transmitter B is also provided on the second pipeline.

[0031] The regulating valve adjusts and controls the sealing differential pressure to ensure that the intake air flow of the carbon ring seal is minimized, avoiding excessive energy efficiency loss of the compressor; the high-temperature and high-pressure gas at the compressor outlet is cooled and dehumidified by the cooler, and the temperature is reduced to less than 40 degrees. Then it passes through the filtering unit to filter and provide clean, dry and low-temperature gas (T less than 40 degrees) for the carbon ring seal to protect the graphite ring, that is, the sealing carbon ring; the differential pressure feedback signal of the regulating valve is provided by the differential pressure transmitter A (PDIT102). The high-temperature differential pressure transmitter uses a capillary type, and the pressure-taking pipeline at the impeller backplate is cooled by a condensate tank. The size of the condensate tank is determined by calculation according to the pipeline pressure and temperature (there are temperature and pressure transmitters in the pipeline). The condensate drainage of the condensate tank is automatically drained by the steam trap. By controlling the regulating valve and the differential pressure transmitter, the differential pressure between the gas pressure entering the first-stage carbon ring and the impeller backplate pressure of the compressor is maintained at a relatively small positive differential pressure, ensuring that there is no leakage of the high-temperature and high-pressure process gas of the compressor. At the same time, the amount of gas injected into the compressor is very small, ensuring the energy efficiency of the compressor. The condensate tank and the automatic steam trap ensure the correct transmission of the signal of the differential pressure transmitter. The differential pressure transmitter A PDIT102 monitors, alarms and interlocks the sealed intake air system to ensure the effective operation of the sealed system

[0032] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A sealing gas intake control and monitoring system, characterized in that: include, The first pipeline has an air inlet end connected to a carbon ring sealed high temperature and high pressure gas source, on which an air inlet regulating valve is arranged; and an air outlet end connected to a carbon ring sealed gas injection port at the shaft end of the compressor to inlet air and take pressure; The second pipeline has its head end connected to the shaft segment seal at the root of the compressor outlet impeller to take pressure; A differential pressure transmitter A, which is connected to the first pipeline and the second pipeline respectively, and is used to measure the pressure difference between the gas pressure entering the carbon ring seal and the pressure at the root of the compressor impeller; The differential pressure signal of the differential pressure transmitter is fed back to the regulating valve, and the regulating valve adjusts the intake pressure and intake flow rate according to the differential pressure signal transmitted by the differential pressure transmitter.

2. A sealing gas intake control and monitoring system as claimed in claim 1, characterized in that: A gas filter unit is arranged on the air inlet end of the first pipeline before entering the regulating valve.

3. A sealing gas intake control and monitoring system as claimed in claim 2, characterized in that: A branch line is set on each of the two end pipelines of the gas filter unit to take pressure, and a differential pressure transmitter B is set to detect whether the filter unit is blocked by detecting the pressure difference change.

4. A sealing gas intake control and monitoring system as claimed in claim 1, characterized in that: On the air inlet end pipeline of the first pipeline, a cooler is provided before entering the regulating valve to cool down the injected high-temperature and high-pressure gas.

5. A sealing gas intake control and monitoring system as claimed in claim 1, characterized in that: A temperature transmitter, a pressure transmitter A and a cooling tank are also arranged in sequence on the second pipeline.

6. A sealing gas intake control and monitoring system as claimed in claim 5, characterized in that: A drain valve is provided at the bottom of the cooling tank for automatically draining the condensed water in the cooling tank.

7. A sealing gas intake control and monitoring system as claimed in claim 1, characterized in that: It also includes an alarm unit, and the differential pressure transmitter A is connected to the alarm unit signal.

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